1. Field of the Invention
The present invention relates generally to plasma display panels and more particularly to a structure of a plasma display panel for multi-screen screen system in which the sealing seams are substantially narrowed, thereby reducing width of noticeable connected portion on the screen.
2. Description of the Related Art
An exemplary prior art plasma display panel (PDP) is shown in FIG. 1. This plasma display panel comprises a front glass plate, a back glass plate, sealing seams 3, barrier ribs 9, phosphor layer 10, and display cells 11. The front glass plat consists of transparent glass sheet 1, transparent electrodes 4, dielectric layer 5, and protective layer 6. The back glass plate consists of a glass sheet 2, addressing electrodes 7, and dielectric layer 8.
The front plate and back plate are bonded together with low melting point glass to form a discharge gas space therebetween. To make four line of sealing seam on the inside surface of the plates along matrix border line, it is necessary to first coat or print the sealing seams 3 with a special sealing material comprising of SiO2, PbO, and B2O3. Consequently, after coating, there is a heat treatment process within the range of temperature of 400° C.–500° C. The front glass plate and back glass plate are then sealed to form a semi-finished assembly of the PDP. Next, the residual gas is drawn from the space between the front glass plate and the back glass plate. Finally, the inert gas is filled into the space to finish the PDP assembly.
Some disadvantages exist in prior art PDPs as illustrated in FIG. 1. The width of the sealing seam displayed on the edge part of the panel is hard to control in coating process and varies depending on the flowability of the glass powder. Consequently, the width of the peripheral edge of light-absent region on the plate is typically within the range of 10 mm–15 mm. It is a big width of the sealing seam. Unfortunately, this means that the light-absent area between adjacent units is noticeable to viewers, and there is a “mosaic” like appearance present on the screen, further degrading the images provided thereby.